In the field of printing technology, a need exists for providing inks that allow for the generation of an image on a printing medium that retains a high image quality over a prolonged period of time, e.g. several years. Potentially interesting types of inks are water-based latex inks. An example of an ink comprising a latex binder is for instance given in PCT patent application WO 2007/112337 by the present applicant. The latex binder is added to the ink to bind the ink to the medium after printing.
In order to cure the latex in the ink following printing, the medium carrying the ink must be exposed to an elevated temperature. To this end, WO 2007/112337 proposes the use of any number of heated pick-up rollers, hot air fans or radiation devices.
In European patent application EP 1 403 341 A1, heating is employed during and after printing of a latex comprising ink on a non-absorbing substrate. The heating steps help spreading the ink over the non-absorbing substrate and accelerate the evaporation of the fluids in the ink solution. The heating steps during and after printing may be employed using light irradiation, a hot air source or an electrical heater.
However, heating a medium during or after reception of a water-based latex ink is not without problems. For instance, certain types of media may develop thermal marks when being exposed to excessive thermal flux. Moreover, the medium may exhibit significant thermal expansion, which is especially undesirable during printing because it can deteriorate the image quality.
Hence, there exists a need for a printing device that overcomes at least some of these problems.